Aliphatic aminoacyl compound and method for preparing same



I Patented Mar. 7, 1944 2,343,769 'rrc AMINOACYL ooMrouNn Ann METHOD FORPREPARING SAME Hugh William Gray,

Wilmington, DeL, asslgnor to E. L'du Pout deNemours & Company,Wilmington, DeL, a corporation of Delaware No Drawing. ApplicationSeptember 21, 1941, Serial No. 412,603

4 Claims. (CL 260-404) This invention relates to. certain new lon chainaliphatic aminoacyl compounds and to methods for their preparation.

Alpha-amino acids in general undergo bimolecular condensation to givediketopiperazines, while the beta-amino acids invariably undergodeamination with formation of. the alpha, betaunsaturated acid. Asdisclosed in application Serial No. 327,324, filed April 1,1940, by W.E. Hanford (now Patent No. 2,312,966, dated March 2, 1943), long chainaminoacids having a radical length of at least seven are readilycondensed intermolecularly to give linear polyamides of high molecularweight. In striking contrast, the long chain amino acids of the presentinvention exhibit a specific intramolecular condensation when Remarkablesubjected to elevated temperatures. stability is evident in thatdeamination does not occur, formation 01' the cyclic lactam being thefavored reaction. This pronounced difierence in reactivity establishesthis new found class of long chain acid compounds as fundamentallydiflerent from the longchain amino acid types of theprior art.-

This invention comprises the discovery of a new class of aliphaticmonoaminomonoacyl compounds having a chain length of at least16 atoms,the amino group being attached to a carbon atom in the chain which. isgamma or delta with respect to the acyl carbon; Such compounds may berepresented by the formula where R. is a bivalent open chain organicradical NH: or ONH4 where M denotes a metal, R "v an. open chainhydrocarbon radical, and'R, R, R"-

and .R' are as indicated above. R, BAR" and 3' may be heteroatomiccontaining oxygen,

(melting point 92 to 94 acids in which R" Serial No. 346,144, filed-Martin, Serial No.

hydrogen. The preferred compounds are the and R' are hydrogen, whichhave chain lengths of 16-22 atoms, and a radical length of 5 or 6, e.g., 4-aminostearic acid.

The aminoacyl compounds of this invention can be prepared from thecorresponding keto acids or keto acid derivatives by catalytichydrogenation, in the'presence of ammonia or primary or secondaryamines, at elevated temperatures and superatmospheric pressures.According to one embodiment of this invention, the conversion can beeffected by bringing into intimate contact in the presence of a suitablehydrogenation catalyst, e. g., nickel, at a temperature between and 150C., and at a pressure between 1500 and 2500 pounds per square inch theketcacyl compound, hydrogen, a primary or secondary amine as describedin the copend'ing (application of M. W. Farlow,

July 18, 1940 now Patent No. 2,323,806, issued July 6, 1943. Theketoacyl compound can be used as the free acid, anhydride, inorganicsalt, ester or amide. Alternatively, the

reduction can be accomplished chemically by: formamide-forming'reactants,

treatment with e. g., [(NHOzCOs-I-HCOOH] in accordance with the generalprocedure, as applied to short chain ketones, by Leuckart, Berichte, 18,2341 (1885).

.The aminoacyl derivative obtained by this trydrogenation' reaction isisolated and purified as described in the copending application of E. L.346,139, filed July 18, 1940, U. S. Patent 2,283,683, issued May 19,1942. The aminoacyl derivative is converted to the amino acid byhydrolytic procedures, the amino acid being purified byrecrystallization from organic solvents or by reprecipitation fromaqueous organic acid solution as described in the aforementionedapplicationoi E. L. Martin.'

The examples which follow set forth certain well defined instances-ofthe application of this invention and are to be considered asvillustrating and not as limiting this'invention. Unless otherwisespecified, the quantities of the ingredients used are given as parts byweight.

. Example 7 g A mixture of 20 parts of 4-ketostearic acid oil asdescribed in Example I in U. 8. Patent No.

2,121,580), 0.5 part parts of sodium hydroxide,

and 70 parts of water is heated in 'a shaker tube nitrogen, or sulfur inaddition to carbon and-o5 with 30 parts of anhydrous ammonia at C.

and either ammonia or 0., obtained from oiticica of ammonium chloride,2.8

2 parts of an alloy-- skeleton nickel, catalyst, 56 parts of methanol,

for 2 hours, and then treated with hydrogen at 2000 lbs/sq. in. for 3hours at the same temperature. 'The solid product is dissolved in 2000parts of hot aqueous sodium hydroxide solution and the catalyst removedby filtration. The pH of the filtrate is adjusted to 7 by addition ofacid, the precipitate which forms is removed by filtration, washed withwater, dissolved in 200 parts of warm 25% formic acid, the solutiontreated with charcoal, and filtered. The filtrate is made alkaline withammonium hydroxide, and

in vacuo at 255 C. Complete sublimation occurs;

the sublimate melting at 86 to 87 C. after recrystallization fromtertiarybutanol. The material is characterized by .its insolubility inaqueous alkali and in aqueous formic acid. and its neutrality in ethanolbenzene solution. This ma-' terial is 4-stearolactam.

'AnaL-Calcd. for stearoiactam, CraI-hsON: N, 4.98. Found: N, 4.58.

The desired aminoacyl compound can be prepared irom the correspondingketoacyl compound by employing the latter as the free acid, amide,ester, anhydride or inorganic salt. The derivatives thus obtained can beconverted by standard hydrolytic procedures to the corresponding aminoacid.

Although ammonia is used in the above example, in place thereof therecan be used a primary or secondary amine in which event the product willbe the N-alkylamino acids.

In general any hydrogenating-dehydrogenating catalyst such as nickel,cobalt, iron, copper, cadmium, zinc, tin, platinum, palladium, or silveris satisfactory, although nickel catalysts are preferred.

Although the hydrogenation pressures used in the above example rangefrom 1500-2500 lbs/sq. in., these figures should not be constructed ascritical. In general the upper limit of pressure is determined mainly bythe typ 01' apparatus used and the lower limit approximates the partialpressure oi ammonia at the temperature employed.

The processes of this invention can be. carried out zit-temperaturesfrom about 25-200 C. When the reduction is carried out catalytically,temperatures in the range of 130 to 150 C. are generally employed.

Yarious times may be allotted to the hydrogenation reaction, from 1-5hours usually being suilicient. A period of initial heating with ammoniabefore introduction :of hydrogen is sometimes desirable, but is notnecessary since satisfactory results are obtained by simultaneousadmission of hydrogen and ammonia or the amine to the reaction mixture.

The amino acids produced in accordance with the processes oi. thisinvention can be purified as described in application Serial No.346,139, filed July 18, 1940, by E. L. Martin, now U. 8. Patent2,283,683, issued May 19, 1942.

In conducting the chemical reduction various substituted formamides andi'ormamide producing, materials can be used; for example, ammoniumformate is a very satisfactory reducing Mminostearic acidGHdCHfluOfHwHQaCmH l im l-aminomlmitic acid OHI(CHI)IQOH(OHI) :0 01B6'aminol1l1mltlc acid CHa(CH|)uCH(OH1)aGO|H I'm.

i-aminomargaric acid CH1(CH!)11CH (CHQJICOaH 1 1m Mminomargario acidQH|(CH1)I1CH(CH1)ICOIH I'm.

4-aminobehenic acid OH;(CH CH(CH )|C 01H r'zm lS-aminobebenio acid CH(CHa)nCH(CHa)|C OsNl l iHr Sodium ii-aminoetearatc CHz(CH|) OH(CHa);C01K 1....

Potassium i-aminopalmitata CH4(CH:)nCH(CH1)aC O|NH| Ammoniumbaminopalmitato crmcno ucmcmhcoicni Methyl l-Aminomarzante CH;(CHg)OH(CHa)|C OaCcHn its.

Iscbutyl 6-aminomu-garate cmwnoncmcnmco,(cn, .cn=on(cno1cm $1M M an. nyl4-amniobchenatc CR.(CH1)1ICH(CH1)ICOI(CH$)1CHI tn. n-0ctylB-aminobehonato cmccmmcmcmhco o IEIHI 4-amiuo eloosanoic anhydridacmcncucmcamc o, Pb )3 Load Mminomargaratc (cmwnonomcmhcoi) ca Calciuml-aminobehonate Iclaini: cmwmmcmcnmc 01H '1. An aliphaticmonoaminomonoacyl compound having a chain length of at least 16 atoms,se-

lected from the class consisting of carbon atom chains and chainscontaining in addition to cart rlaminolstwi i bon an atom from the.group consisting of oxygen QH,(QH,)"CH(QH,)CQ3H and sulfur, the aminogroup being attached to a l carbon atom in the chain which is separatedfrom I the acyl carbon by a chain of two to three atoms 1 i= selectedfrom the class consisting of carbon atom H chains and chains containingin addition to car- 5 (N, t ]m id6)b h l acid bol:i alnuatom from thegroup consisting of oxygen an s ur. 2. A compound bf the general formulao a H (3:0 R{-GHR-C/ 11 i-iormamidomelisslo R/ RII! f wherein R is abivalent aliphatic hydrocarbon N radical containing two to three carbonatoms in contiguous relation, 'R is a monovalent aliphatic hydrocarbonradical, R" and R' are selected F Hmylamm) from the class of hydrogenand monovalent open cmwnoucmcnmconm chain organic radicals selected fromthe class conr sisting of carbon atom chains and chains contraining inaddition to carbon an atom from the =0 group consisting of oxygen andsulfur, and R. 1!! and R are so chosen that the chain lengthHmidomemamde R'-CHRC is at least 16 carbon atoms, A is 0 selected fromthe-class 01. OH, --OM, OR

HI cm cmm mkcmncon N N H as Ci' (h s R RN-methyl-4(ethylmethylamino)hexide -NH:, and ONH4, where M denotes ametal and R is an open chain hydrocarbon radical. c o n f '3. A compoundhaving the general formula NH: 40 b amino-a-thia-nonadecanoic acidcmwzmuocmcmcncmcmcon!' a N A v 4'amino-7-oxa-eieosanoic acid H ments ofthis invention may be made without de- A parting from the spirit andscope thereof, it is where R is a bivalent open chain organic radical, Ris a monovalent aliphatic hydrocarbon radical, and R and R are so chosenthat the chain length R"CHH is between 16 and 22 carbon atoms and theradical length NCR--C is 5 or 6 'carbon atoms and where A is selectedfrom the class ocon( m n NH: y -NH:, and ONH4, where M denotes a metalto be understood that this invention is not to be and R" anopen chainhydrocarbon radical.

limited to the specific embodiments shown and described.

4. i-aminostearic acid.

' HUGH GRAY.

